2.The blood-sucking parasites which attack the outside of the host are called __. 3.A lichen is an example of mutualism between a __ and an __.
4.__ has taken up home in the empty shell of whelks.

2.ecto parasite

3.Algae and Fungi

4.

explanation:

the last one: artificial selection/genetic engineering

plant breeding is modifying the genetic composition of the plant - but this isn't cloning (which is specifically introducing a gene into a genome). but you are artificially selecting for the phenotype that you want.

the second one is literally genetic engineering - the gene would have been cloned first and then inserted or genetically engineered into the new plant cell (the cotton).